How accurate are dangerous global warming forecasts? An Australian university prefessor reports they are "All up in the air", according to the Courier Mail 30 June 2007. Professor Bob Carter, a James Cook University geologist, who studies ancient environments and climate, commented on the latest admission of weather guru Kevin Trenberth, head of the US National Centre for Atmospheric Research and one of the advisory high priests of the UN's Intergovernmental Panel on Climate Change (IPCC). Trenberth has had a distinguished career as a climate scientist with interests in the use of computer General Circulation Models (GCMs), which are the basis for most current public alarm about dangerous global warming. Carter writes "In a remarkable contribution to Nature magazine's Climate Feedback blog, Trenberth now concedes (writes Carter) that GCMs cannot predict future climate and claims the IPCC is not in the business of climate prediction. Among other things, Trenberth asserts "… there are no (climate) predictions by IPCC at all. And there never have been". Instead, there are only "what if" projections of future climate that correspond to certain emissions scenarios. According to Trenberth, GCMs "do not consider many things like the recovery of the ozone layer, for instance, or observed trends in forcing agents … None of the models used by IPCC is initialised to the observed state and none of the climate states in the models corresponds even remotely to the current observed climate. The state of the oceans, sea ice and soil moisture has no relationship to the observed state at any recent time in any of the IPCC models. There is neither an El Nino sequence nor any Pacific Decadal Oscillation that replicates the recent past; yet these are critical modes of variability that affect Pacific rim countries and beyond … the starting climate state in several of the models may depart significantly from the real climate owing to model errors" and "regional climate change is impossible to deal with properly unless the models are initialised".

GCMs "assume linearity" which "works for global forced variations, but it cannot work for many aspects of climate, especially those related to the water cycle . . . the science is not done because we do not have reliable or regional predictions of climate". Strange that (says Carter) who could have sworn that I heard somewhere that the science was supposed to be settled. One wonders whether anyone has told the CSIRO (Commonwealth Scientific and Research Organization) that their much-vaunted regional climate models are worthless predictive tools. Perhaps someone will ask the CSIRO to refund the amounts state governments and others have paid for useless regional "climate forecasts"? In another devastating blow to the credibility of climate forecasting, a lead author of the IPCC Working Group 1 science report, Jim Renwick, recently admitted "climate prediction is hard, half of the variability in the climate system is not predictable, so we don't expect to do terrifically well". Renwick was responding to an audit showing the climate forecasts issued by New Zealand's National Institute of Water and Atmosphere were accurate only 48 per cent of the time. In other words, one can do just as well by tossing a coin. Carter states, "These various criticisms of climate modeling can be summed up in the following statement - there is no predictive value in the current generation of computer GCMs and therefore the alarmist IPCC statements about human-caused global warming are unjustified."

Editorial Comment: Australia is only one of many democratic countries in which both Government and the Opposition parties profess to set climate policies based on IPCC advice, as they legislate with gay abandon to impose inefficient, ineffective and costly carbon trading or taxation system on their economies, with the alleged aim of "stopping climate change". Is it time to tell the leaders of such Governments that dangerous global warming has been called off?